Method of using 4-arylbicyclo(2.2.2)octyl urethans as antidepressants and compositions thereof

ABSTRACT

THIS INVENTION TEACHES THE PREPARATION OF 5-ARYLBICYCLO (2.2.2) OCT-1-YL URETHANS AND METHODS OF USING AND FORMULATING THE SAME AS ANTIDEPRESSANT AGENTS. REPRESENTATIVE OF THE COMPOUNDS WITHIN THE SCOPE OF THIS INVENTION ARE ETHYL N-4-PHENYLBICYCLO (2.2.2) OCT-2-EN1-YL URETHAN AND PROPYL N - 4 - (O-TOLYL) BICYCLO (2.2.2) OCTANE-1-YL URETHANE.

United States Patent 01 lice 3,595,962 Patented July 27,, 1971 US. Cl. 424274 6 Claims ABSTRACT OF THE DISCLOSURE This invention teaches the preparation of 4-arylbicyclo [2.2.2]oct-1-yl urethans and methods of using and formulating the same as antidepressant agents.

Representative of the compounds Within the scope of this invention are ethyl N-4-pheny1bicyclo[2.2.2]oct-2-enl-yl urethan and propyl N 4 (o-tolyl)bicyclo[2.2.2] octane-l-yl urethan.

CROSS REFERENCE TO RELATED APPLICATION This application is a divisional and continuation-inpart of my copending application Ser. No. 697,302, filed Jan. 12, 1968, now U.S. Pat. 3,507,957.

BACKGROUND OF THE INVENTION This invention relates to methods of using 4-arylbicyclo[2.2.2]oct-1-yl urethans as pharmaceutical agents. More particularly, this invention relates to said 4-ary1- bicyclo[2.2.2]oct-1-yl urethans which can be used as antidepressant agents.

Before the late 1950s no adequate pharmaceutical agent was known which could be used for the treatment of depression, and the medical arts had to rely on psychotherapy for treating mild depressions and. electroconvulsive therapy to counteract severe depressions.

Then, in the late l950s, the first truly effective pharmacological agents useful for treating various depressive syndromes were developed. These agents were lumped together as a class known as monamine oxidase (MAO) inhibitors based on their ability to inhibit the metabolic oxidative deamination of naturally occurring amines such as dopamine and tyramine. These MAO inhibitors comprise a heterogeneous group of drugs having in common this ability to inhibit the metabolic oxidative deamination of naturally occurring amines.

A later development in the treatment of depression was the discovery that dibenzazepine derivatives could be used to treat depressive syndromes. These agents are thought of as the successors to the MAO inhibitors and although their mode of action is not well understood, they are effective antidepressants.

The discovery of the above described agents as useful therapeutic agents for treating depressive syndromes has presented psychotherapy with a useful tool that can and has been advantageously used in the management of depression.

There is however, a continuing need for new agents in this field. It is in this field of antidepressive agents that the compounds of this invention are useful and can contribute to the progress of the medical arts.

SUMMARY OF THE INVENTION I have discovered that the N-4-arylbicyclo[2.2.2]oct-lyl urethans are useful as antidepressant agents. For the purposes of this description, the term N-4 arylbicyclo [2.2.2] oct-l-yl urethans includes the following types of compounds:

N-4 phenylbicyclo[2.2.2]oct-2-en-l-yl urethans, N-4- substituted-phenyl) bicyclo [2.2.2] oct-2-en-l-y1 urethans, N-4 phenylbicyclo[2.2.2]octane-l-yl urethans and N-4- (substituted-phenyl)bicyclo[2.2.2]octane-l-yl urethans.

The compounds for use according to the method of this invention are represented by the following formulae:

where R is alkyl of 1 through 8 carbons, ethyl pyrrolidinyl or phenyl; and R and R are hydrogen, methyl, ethyl, chlorine, bromine, fluorine, nitro, amino, dialkylamino where each alkyl group has 1 through 4 and preferably 1 through 2 carbons, cyano, alkoxy of 1 through 4 and preferably 1 through 2 carbons, alkoxycarbonyl where the alkyl group has 1 through 2 carbons, or trifluoromethyl; and

-NHCOOR (In R Where R is alkyl of 1 through 8 carbons, ethylpyrrolidinyl or phenyl; and R and R are hydrogen, methyl, ethyl, chlorine, bromine, fluorine, nitro, amino, dialkylamino where each alkyl group has 1 through 4 and preferably 1 through 2 carbons, cyano, alkoxy of 1 through 4 and preferably 1 through 2 carbons, alkoxycarbonyl Where the alkyl group has 1 through 2 carbons, or trifluoromethyl.

Salts of the above compounds with non-toxic anions are included within the scope of this invention where such salt formation is possible. Representative acids from which said anions are derived include hydrochloric acid, sulfuric acid, phosphoric acid, acetic acid, succinic acid, adipic acid, propionic acid, tartaric acid, citric acid and carbonic acid.

Preferred compounds of this invention are those of Formulae I-II in which R is as defined above and R is hydrogen, methyl, ethyl, chlorine, bromine, fluorine, nitro, amino, dialkylamino where each alkyl contains from 1 through 2 carbons, alkoxycarbonyl where the alkyl contains from 1 through 2 carbons, and trifluoromethyl.

Particularly preferred of the compounds are those where R is alkyl containing from 1 through 4 carbons and R is hydrogen.

'Also includedwithin the scope of this invention is the method of producing an antidepressant effect in warmblooded animals which comprises administering to said warm-blooded animal one or more compounds of Formulae I and II in admixture with other pharmaceutical- 1y useful antidepressant compounds.

DESCRIPTION OF THE INVENTION The compounds of Formulae I and II can be prepared by converting a 4 arylbicyclo[2.2.2]oct-2-en-lcarboxylic acid to the corresponding 4-arylbicyclo[2.2.2] oct-2-en-l yl urethane by a modified Curtius reaction [1. Org. Chem. 26, 3511 (1961)] in which a mixed anhydride of the acid is formed with ethyl chloroformate and then treated with sodium azide to form the acid azide. This is heated in toluene to cause rearrangement to the isocyanate, which is treated with an alcohol to form a urethane of this invention.

3 The 4 arylbicyclo[2.2.2]oct 2 ene 1 carboxylic acid starting materials for the above described reaction can be prepared generally as follows.

A mixture of 6-aryl-u-pyr0ne-3-carboxylic acid ethyl 4 EXAMPLE 1 A solution of 16 ml. (11.6 g., 0.115 mole) of triethylamine in 100 ml. of acetone is added to a stirred mixture of 22.8 g. (0.10 mole) of 4-phenylbicyclo[2.2.2]oct-2- ester and benzene is mixed with ethylene in a suitable 5 1- pressure vessel which is then pressured up to 1000 at- T2 f gggg g i s i g 33 232; g i g mospheres at a temperature of under 200 C. The system IS ole 6th 1 chloroformate in 50 m1 of ace'to pressure is increased to up to 3000 atmospheres with ethyld 32 g Wise ywith Coolin at a rate slich that the cue and the elevated temperature is maintained for up to a t 5 t Ii abovegoo c when the addition 13 hours' From time to time during this reaction phase 10 i r h le tg stir r in is ci ntinued for 30 minutes and then it is necessary to repressure the system with ethylene to g a solution of 9.8 g. (0.15 mole) of sodium azide in 30 mamtam the p 10p er pressure 1 of water added dro wise at to 0 C After The pressure vessel is then cooled and the contents disz lete Stirrinp is continued for 1 hol'lr The Charged diluted with ethanol and filtered" The alcohol :old so iu t ion is diluted wit h ice water and is extracted and benzene are distilled off, leaving ethyl 4-arylbicyclo- 15 with toluene. The toluene solution is dried with anhy- [2'2'2]octa'en-bcmboxylate' drous ma nesium sulfate is filtered and is heated on a The ethyl 6aryl'wpyrone 3 carboxylate can be Obsteam bath until the evolution of nitro en is com lete tained by the method of Kochetkov et al., J. Gen. Chem. g p s Then, 0.10 mole of methanol and 5 ml. of triethylamine USSCSR (English Translation) 28, 1562 (1958).

are added and the mixture is heated at reflux for 16 hours. The ethyl 4-arylbicyclo[2.2.2]oct 2 ene 1 car- 20 On cooling, the solutlon yields methyl N-4-phenylbicycloboxylate 1s saponified by heating with aqueous SOdllll'l'l lurethan MP 14154430 c hydroxide until dissolved and then acidifying to precipiy tate the acid. The acid is filtered 01f, washed and dried. EXAMPLES Alternatively saponification can be effected by heating with sodium hydroxide in diethylene glycol at 160 C. 25 Example 1 is repeated, substituting 0.10 mole of the for two hours. indicated reactant for the 4-phenylbicyclo[2.2.2]oct-2-ene- In addition to the above descriptions of the preparation l-carboxylic acid and the indicated alcohol for methanol.

Example Acid Alcohol Product 2 4-phcuylbicycl0[2.2.2]ect-2enc-l-carboxylic acid Ethanol EthylN-4-phenylbicyclo-[2.2.2]oct-2-en-1-yl urethan. 3 ..d0 Benzyl alcohoL. BenzylN-4-phenylbicycl0l2.2.2]oct-2-en-1-yl urethan. 4 4-(p-tolyl)bicycle[2.2.2]-oct-2-ene-1-carboxylic acid. Ethanol Ethyl N4-(p-tolyl)bicycle-l2.2.2]oct2-en-l-yl urethan. 5 4 (pw(iithylphenyl)bicycle-[2.2.2]Oct-Z-ene-I-carboxylic do Ethyl}N-4-(p-ethylphenyl)-bicycl0[2.2.2]0et-2-en-1-yl aei uretian. 6 4(p i(liuorophcnyl)bicyclo-[2.2.2]0ct-2-ene-1-carboxylic Butanol Butyl Ni4(p1'luor0phenyl)-bicyclo[2.2.2]0ct-2-en-1- aci y urotian. 7 4-(p-chl0rophenyl)bicyclo-[2.2.2]oct-2-o11c-1-carb0xylic Isopropanol Isopropyl N-4-(p-chloroplienyl)l)icyclo[2.2.2]oct-2- acid. en-l-yl urethan. S 4-(p-bromophenyl)bicycle-[2.2.2]0ct-2 nc-1-carboxylic l-octanol 11-Octyl N-4-(p-broinophenyl)-bicyclo[2.2.2]oct-2- acid. cn-l-yl urethan. J 4-(p-rg anophenyl)bicyel0-[2.2.2]oct-2-one-1-carboxylic Propanol Propyl NIA-(p-cyaiwphenyI)-bicyclo[2.2.2]oct-2en-laci yluretian. 10 4-(1l-llltl013ll0llyl)biCYClO-[Q.2-2100t-2-0l10-1-C&lb0Xy1i0 2-metl1oxy ethanol Z-methoxyethyl N-4-(p-nitropl1onyl)bicyclo[2.2.2]-

acid. oct-2-enlyl urethan. 11 4-(p-moth0xyphcnyl)bicyclo-[2.2.2]oct-2-el1e-1car- Ethanol Ethyl NA-(p-methoxyphenyl)-bicyclo[2.2.2]oet-2- boxylic acid. en-l-yl urethan. 12 4-(p-n1cthoxycarl)ouylphcnyl)-bicyclo[2.2.2]oet-2- l\let.hanol Methyl N-4-(p-methoxycarbonylphenyl)bicycloene-l-carboxylic acid. [2.2.2loct-2en-l-yl urethan. 13 4-(p-etl1oxyearbonylphcnyl)-bicyclo[2.2.2]oct-Z-ene- Ethanol Ethyl N4-(p-eth0xycarbonyl-phenyl)bicyclo[2.2.2]-

1carhoxylic acid. Oct-Zen-l-yl nrethan. 14 4-(m-tolyl)bicycle[2.2.21-0ct-2-ene-l-carb0xylic acid... 2-dimethylan1ino cthanol 2-din1ethylaminoethyl-NA-(rn-tolyl)hicyclo[2.2.2]-

oct-2-eu-l-yl urethan. 15 4-(m-lluorophenyl)bicyole-[2.2.2]oct-2ene-l-carhoxylic Z-pyrrolidyl ethanol 2-pyrrolidylethyl N--(m-fiuorophenyl)bicycloacid. [2.2.2]-0ct-2-enlyl urethan. l6 -(ni-bromophcnyl)bicycle-[2.2.2]0ct-2-cne-1-car- Hexanol Ilexyl N-4-(m-bron10phenyl)-bicyclo[2.2.2]oct-2-enboxylic acid. l-yl urethan. 17 l-(m-metlioxyphenyl)bicy010*[2.2.2]0ct-2-ene1-car- Heptanol Heptyl N-4-(rnmethoxyphenyl)bicycl0[2.2.2]0ct-2 boxylic acid. en-l-yl urethan. 18 4-(m-incth0xyearbonyl-phenyl)bicycl0[2.2.2]0ct-2- Propanol Propyl N-4-(rn-methoxycarbonylphonyl)bicycloene-Learboxylic acid. [2.2.2]oet-2-en-l-yl urethan. 19 4-(m-ethoxycarbouylphenyl)-bicycl0[2.2.2]0ct-2-ene- 2butanol 2-butyl NA-(m-etlioxycarbonylphenyl)bicyclel-earboxylic acid. [2.2.2]oct-2en-l-yl urethau. 20 4-(o-t0lyl)bicyclo[2.2.2l-oct-2ene-l-carboxylic acid Ethanol Ethyl N-4-(0-tolyl)hicyclo[2.2.2]0et2-en-1-ylurethan. 2L 4-(o-iluoropl1enyl)bicycle-[2.2.2]oct-2-cnel-car Methanol Methyl N-4-(o-11uorophenyl) bicycl0[2.2.2]0ct-2en-lboxylic acid. yl urethan. 22 4-(ochlorophenyl)bicycle[2.2.2]0ct-2ene-l-cardo Methyl N-4-(o-chlorophenyl)-bicyclo[2.2.2loct-2-on-1- boxylic acid. yl urethan. 23 4-(o-bromophcnyl)bicycle[2.2.2]oct-2ene1-can Propanol Propyl N-4-(o-broniophenyl)-bicyclo[2.2.2]0ct-2-enboxylic acid. l-yl urethan. 24- 4-(o-nitrophenyl)bicycle[2.2.2]0ct-2-ene-1-car- Z-methoxy ethanol Z-mothoxyethyl N-4-(0-nitr0phenyl)bicycl0[2.2.2]-

boxylic acid. oct-2-en-l-yl urethan. 25 4-(2,4-dimetliylphenyl)bicyclo[2.2.2]0ct-2-ene-1- Butanol Butyl N-4-(2,4-dimethylphenyl)bicyclo[2.2.2]0ctcarboxylic acid. 2-eu-l-yl urethan. 21L 4-(3,S-dimethylphenyDbicyclo[2.2.2]0ct-2euc-1- EthanoL Ethyl N-4-(3,5-dimethylphenyl)bicyclo[2.2.2]octcarboxylic acid. Zen-l-yl urethan. 27 4-(3,4-dimetlioxyphenyl)bicyclo[2.2.2]0ct-2-cn0-1- Methanol Ethyl N-4-(3,4-dimethoxyphenyl)bicycl0[2.2.2]0ctcarboxylic acid. Zen-l-yl uretlian M1. 1235-12 1" C. 28 4-(3-bromo4-methoxyphenyl)-bicyclo[2.2.2]0ct1- Hexanol I-Iexyl N-4-(3-br0mo-4-rnethoxyphenyl)bicyclo[2.2.2]-

carboxylic acid. oct-Z-en-l-yl-urethan. 29 Mil-nitro--methoxypheuyl)bicycl0[2.2. ]00t-2-e11c- Methanol Methyl N-4(3-nitro-l-methoxyphenyl)bicyclo[2.2.2]-

l-carboxylic acid.

oct-Z-en-l-yl urethan.

of the compounds of this invention, a better understanding of my invention will be gained by reference to the following examples illustrating the preparation of representative compounds of this invention.

EXAMPLE 30 A solution of g.of ethyl 4-phenylbicyelo[2.2.2]oct- 2-ene-1-carboxylate in ml. of ethanol is hydrogenated 6 for 16 hours at atmospheric pressure. A solution of 0.2 M chloroplatinic acid initially is added to the solution EXAMPLES 32-54 until uptake of hydrogen commences. The catalyst is By substituting a lower alkyl ester of the desired 4-arylfiltered OE and the solvent is evaporated. The residue is bicyclo[2.2.2]oct-2-ene-1-carboxylic acid for the ethyl recrystallized from methanol to give 22.2 g. of ethyl 4- 5 4-phenylbicyclo[2.2.2]oct-2-ene-l-carboxylate in Examphenylbicyclo[2.2.2]octane 1 carb x late, M P 68- ple and then substituting the resultant arylbicyclo- 69 C, [2.2.2]octane-l-carboxylic acid for the 4-phenylbicyclo- A mixture of 11 g. of ethyl 4 phenylbicyclo[2.2.2]- [2.2.2]octane-l-carboxylic acid in Example 31 and by octane-l-carboxylate and 1000 ml. of 2 N sodium hyusing the indicated alcohol, the indicated urethans may droxide solution is refluxed for 16 hours with stirring. The 10 be P p Example Acid Alcohol Product 3 4-o-tolylbicyclo[2.2.2]-octane-1carhoxylic acid MethanoL Methyl N t-o-t0lylbicyc1o[2.2.2]octan-1-y1 r tha 33 4-m-tolylbicyclo[2.2.21-octane-l-carboxylic acid Propanol. Propyl N-4-m-tolylb1cyclo[2.2.2]0ctan-1-yl urcthan. 34" 4-p-tolylbicyclo[2.2.2]-octane-l-carboxylic acid Octanol Octyl N-4-p-tolylb1cyclo[2.2.2]octan-l-yl urethan. 35-.. 4-p-elg1ylphenylbioyclo-[2.2.2]octane-l-carboxylic Z-propanoL- d ner g1 N-4-p-othylphenylbicyclo[2.2.2]octan-1-yl aci me an. 36 4-(2,4-dimethyl)phenylbicyclo[2.2.2]octane-1- Ethanol Ethyl N-4-( ,4-di111ethy1)bicyol0[2.2.2]octan4-yl carboxylic acid. urethan. 37 4-(3,5-dimethyl)phenylbicyclo[2.2.2loctanc-1- Hcxanol HcXylN-4-(3.5-d11netl1ylphenyhbicyclo[2.2,2]0etancarboxylic acid. l-yl urethan. 38 4(2,6-dimethyl)phenylbicyclo[2.2.2]octane-l- Propanol PropylN-4-(2,fi-dimethylphcnybbicye10[2.2.2.]

carboxylic acid. octan-l-yl urethan, 39 4-(4-ethyl 2-methylphenyl)-bicyclo[2.2.2]0ctane-l- Methanol Methyl N4-(4'othyl-2-methylphenyl)bicyclo[2,2,2] carboxylic acid. octan-l-yl urethan. 40 4-(2A-diethylphenyl)bicyclo[2.2.2]octane1- Ethanol Ethyl N4-( ,4-d1cthylphenyl)b1cyc1o[2.2.2]oetan-1 carboxylic acid. yl urethan. 41 4-(p-fluorophenyl)bicyclo[2.2.2]octane 1-carboxylic Pentanol Pen y l N-4(p-flu0ropheny1)b1cyclo[2.2.2]octan-1- 1 acid. me an. 42 4-(p-ch1orophenyl)bicycle-[2.2.2]octane-1-carboxylic Butanol Butyh?!4-(p-chlorophenyl)bicyclo[2.2.2]octan-1-y1 aci me an. 48 4-(p-bromophenyl)bicyclo-[2.2.2]octane-l-carboxylic Heptanol l. l'lcpty l N-4-(p-brOmophenyDbicyclo[2.2.2]0ctai1-1-y1 aci we ran. 44 4-(o-chlorophenyl)bicycle-[2.2.2]octane-l-carboxylic Allyl alcohol Allylt1;4-(0 chlorophenyhbicyclo[2.2.2]octan-1-y1 acid. ure an. 45 4-(0-bromophenyl)bicyclo-[2.2.2]octane-l-carboxylic 2rncthoxyethanol 2-mt thoi rye thyltgl-4-(o-bromopheny1)bicyc1o[2.2.2]

aci 00 an- -y are an. 4 4-(o-chlorophcnyl)bicycle-[2.2.2]octane-1-carboxylic Methanol Methyll1 N-4-(0-chlorophenyl)bicyc1o[2 2,2] tan-1 1 acid. me an. 4-(p-bromopl1enyl)bicyclo-[2.2.2]octane-1-carboxylic Etl1ano1... l Ethyhlfl4-(p-br01n0phenyl)bicyclo[2.2.2]octan-1-y1 acid. ure an. 48 4-(p-mcthoxyphenyl)bicyclo-[Z.2.2]0ctano-ld0 Ethyl N-4-(p-mcthoxyphenyhbicyclo[212121octan-1- carboxylic acid. yl urcthan.

M.P. l08.5l09 C. 49 4-(p ethoxyphenyl)bicyclo [2.2.2]0ctane-l- 2-butan0l 2-bu yl N4-(p-eth0xyphenyl)b1cycl0[2.2.2]octan-1- carboxylic acid. yl urethan. 50 4-(2,4-difluorophenyl)-bicyclo[2.2.2]octane-1- Z-propaliol pr0pyl N-4-(2,4- 1fluoropheny1)b1cye10[2.2.2]

carboxylic acid. octan-l-yl urethan. 51 4-(2-chloro-4-fiuoi'ophenyl)bicyclo[2.2.2]octane-1 Butanol Bu ylN-4-( -chloro4-fiuoropheny1)b1cyc1o[2.2.2]

carboxylic acid. octan-l-yl urcthan. 52 4-(2,4-dimethoxyphenyl)bicycl0[2.2.210ctane-l- 2 pyrro11dy1e ha l y y t ylN-4-(2,4-d1methoxyphcnyl)b1cyclo carboxylic acid. [2.2.2]octan-l-yl urethan. 53 4-(3,4-dimethoxyphenyl)-bicyclo[2.2.2]octane-1- Ethanol E yl 4-(3, -dlmethoxyphenyl)b1cyclo[2.2.2]

carboxylic acid. octan-1y1 urethan. 54 4-(2,4-dinitrophenyl)-bicyclo[2.2.2]octane-1- H.110 E ylN-4-(2,4-d1n1tropheny1)b1cyclo[2.2.2]octan-1- carboxylic acid. yl urethan.

mixture is allowed to cool slightly and is acidified with 45 EXAMPLE 55 concentrated HCI so that the temperature 18 held at A container of a material resistant to hydrogen fluoride -1000 coPling the acidified Solution give? attack (as for example, platinum, Hastelloy steel, or of 4 Phenylblcyclo[22-210mm 1 Carboxyhc polyethylene) is cooled with solid carbon dioxide and which a be Purified by recrystoanization from acfitic acetone and is charged With about 50 ml. of anhydrous acid to g1ve crystals, M.P. 27Z279 C. A samp e Pllflfied 50 hydrogen fluoride. The liquid is stirred and 11.8 g. (0.0432 for analysls melts 0 mole) of ethyl N-4-phenylbicyclo[2.2.2]octan-1-yl ure- Analysis.Calcd. for C 1 z C, 78.23%; H, 188% than is added. Then 2 ml. 3.00 g., 0.043 mole) of turning Found: C, 77'76% 771% (Molnitric acid is added slowly. The cooling bath is removed and the solution is allowed to stand for 16 hours.

EXAMPLE 31 Tlio hydrogen fluoride is evaporated, the residue is disso ved in dichloromethane and is washed with 10% z g g i g i g sodium carbonate solution. The dichloromethane solution -pl iggylbi cyc zl fl 2] c?arle-lcarl oxy lic acid I d is ied with nhydrous magnesium sulfate and evaporated. 300 ml. of acetone. This solution is cooled to 5 to 0 C. 60 The resldue ls pnmanly ethyl N 4 (p'mtrophenyl) blcyclo' and a solution of 12.0 g. of ethyl chloroformate in 50 [zz'noctan-lnyl urethan' ml. of acetone is added dropwise, with cooling, at a rate EXAMPLE 56 such that the temperature does not rise above 0 C. When H drazine h drate 20 i d o addition is (1mP16te, $tirring is continuefi for sion bf 1 teasp on of lQaney riicfiel in iiliiii n ol lgill minutes, and then a solut1on of 9.8 g. of sodium azide 55 mole f ethyl N 4 (pmitrophenyl)bicyclonzz]oct 2 en 111 30 Q f 15 added Q QP F at to l-yl urethan in 500 ml. of ethanol at 70 C. When the After addltlon 1S F P Q' Surfing 1S confirmed for 1 addition is complete, the mixture is cooled and the cath The Cold 8011111011 15 diluted With ice Water and is alyst is filtered off. The filtrate is evaporated to give ethyl extracted with toluene. The toluene solution is dried with N-4-( i h l)bi l 2,21 .2- 1 1 uretham anhydrous magnesium sulfate, is filtered, and is heated 70 on a steam bath until the evolution of nitrogen is com- EXAMPLES 57-60 plete. Then, 0.10 mole of ethanol and 5 ml. of triethyl- The procedure of Example 56 is repeated substituting amine are added and the mixture is heated at reflux for 0.040 mole of the indicated reactant for the ethyl N-4- 16 hours. On cooling, the solution yields ethyl N-4-phenyl- (p-nitrophenyl)bicyclo[2.2.2]oct 2 en-l-yl urethan of bicyclo[2.2.2]octane-1-yl urethan, M.P. -111 C. 75 Example 56.

Ex. Product 7- Methyl N-4-(m-nitrophonyD- bicycle[2.2.2]oct-2-en-l-yl urethan.

58 Butyl N -4-(o-nitrophenyD- bicyclo[2.2.2]0ct-2-en-1-y1 urethan.

59- Ethyl N-4-(3nitro-4-methoxyphonyl)bieyelo[2.2.2]oct-2- en-1yl urethan.

00. Ethyl N-4-(p-nitrophenyl)- Reactant Methyl N-4-(m-aminophenyl) bicyclo[2.2.2]oct-2-en-l-yl urethan.

Butyl N-4(oaminophenyl)- bicycl0[2.2.2]oct2-on -1-yl urethan.

Ethyl N-4-(p-aminophenyD- bieyclo[2.2.2]0ctan 1yl bicyclo[2.2.2]octan-l-yl urethan. urethan.

EXAMPLE 61 A 0.5 g. quantity of Pd on charcoal is added to a solution of 40 g. of methyl N-4-(m-nitrophenyl)bicyclo[2.2.2]oct-2-en-1-yl urethan in 200 ml. of ethanol. The mixture is shaken under 50 lb. per sq. in. of hydrogen for 16 hours. The catalyst is filtered ofif and the solvent is evaporated. The residue is methyl N-4-(m-aminophenyl)bicyclo[2.2.2]octan-1-yl urethan.

The compounds for use in the method of this invention can be administered for antidepressant effect according to this invention by any suitable means. For example, administration can be parenteral, that is subcutaneous, intravenous, intramuscular, or intraperitoneal. Alternatively or concurrently, administration can be by the oral route.

The dosage administered will be dependent upon age, health and weight of the recipient, the kind of concurrent treatment if any, frequency of treatment, and intensity of the antidepressant response desired. Generally, a daily dosage of active ingredient compound will be from about 0.01 to 10 and preferably 0.05 to 2.5 milligrams per kilogram per day is effective to obtain the desired result.

Ethyl, N-4-phenylbicyclo[2.2.2]oct-2-ene-1-yl urethan, a compound for this invention, strongly indicates antidepressant activity, as is established when said compound, administered orally to mice at a dose of 5.0 mg. per kg. of body weight, successfully demonstrates protection against tetrabenazine-induced sedation.

The active ingredient for this invention can be employed in useful compositions according to the present invention in such dosage forms as tablets, capsules, powder packets, or liquid solutions, suspensions, or elixirs, for oral administration or liquid solutions for parenteral use, and in certain cases, suspensions for parenteral use. In such compositions the active ingredient will ordinarily always be present in an amount of at least 0.01% by weight based on the total weight of the composition and not more than 90% by weight.

Besides the active ingredient of this invention the composition will contain a solid or liquid non-toxic pharmaceutical carrier for the active ingredient.

In one embodiment of a pharmaceutical composition of this invention, the solid carrier is a capsule which can be of the ordinary gelatin type. In the capsule will be from about 150% by weight of an N-4-arylbicyclo- [2.2.2]octanor oct 2 en 1 yl urethan for this invention and 99-50% of a carrier. In another embodiment, the active ingredient is tableted with or without adjuvants. In yet another embodiment, the active ingredient is put into powder packets and employed. These capsules, tablets, and powders will generally constitute from about 0.5% to about 95% and preferably from 1% to 50% by weight of active ingredient. These dosage forms preferably contain from about 0.5 to about 250 milligrams of active ingredient, with from about 1 milligram to about 50 milligrams most preferred.

The pharmaceutical carrier can, as previously indicated be a sterile liquid such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, for example peanut oil, soybean oil, mineral oil, sesame oil, and the like. In general, water, saline, aqueous dextrose (glucose) and related sugar solutions and glycols such as propylene glycol or polyethylene glycols are preferred liquid carriers, particularly for injectable solutions. Sterile injectable solutions such as saline will ordinarily contain from about 0.05% to 25%, and preferably about 0.1% to 5% by weight of the active ingredient.

As mentioned above, oral administration can be in a suitable suspension or syrup, in which the active ingredient ordinarily will constitute from about 0.01 to 5%, and preferably about 0.02 to 1% by weight. The pharmaceutical carrier in such composition can be a watery vehicle such as an aromatic water, a syrup or a pharmaceutical mucilage.

Suitable pharmaceutical carriers are described in Remingtons Pharmaceutical Sciences by E. W. Martin, a well-known reference text in this field.

In addition to the exemplary illustrations above, the following examples further explain one aspect of the present invention:

EXAMPLE 63 A large number of unit capsules are prepared for oral administration by filling standard two-piece hard gelatin capsules weighing about 25 milligrams each with 50 milligrams of powdered ethyl, N-4-phenylbicyclo[2.2.2]oct- 2-ene-l-yl urethan, 125 milligrams of lactose and 1 milligram of Cab-o-sil finely divided silica.

EXAMPLE 64 A large number of unit capsules are prepared for oral administration by filling soft gelatin capsules with a solution of benzyl N-4-phenylbicyclo[2.2.2]oct-2-ene-1-yl urethan in mineral oil.

EXAMPLE 65 A large number of tablets are prepared by conventional procedures so that the dosage unit is 10 milligrams of active ingredient, 5 milligrams of gelatin, 1.5 milligrams of magnesium stearate and milligrams of lactose. Slow release tablets can also be used, by applying appropriate coatings.

A large variety of compositions according to this invention can thus readily be made by substituting other compounds for this invention, and including specifically but not limited to compounds for this invention that have specifically been named hereinbefore. The compounds will be used in the amounts indicated in accordance with procedures well known and described in the Martin text mentioned above.

Since many different embodiments of the invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited by the specific illustrations except to the extent defined in the following claims.

What is claimed is:

1. A method for producing an antidepressant effect in a warm-blooded animal comprising administering to said animal an antidepressant effective amount of a compound selected from the group consisting of where R is alkyl of 1 through 8 carbons, ethyl pyrrolidinyl or phenyl; and R and R are hydrogen, methyl, ethyl, chlorine, bromine, ,fluorine, nitro, amino, dialkylamino where each alkyl group has 1 through 4 and preferably 1 through 2 carbons, cyano, alkoxy of 1 through 4 and preferably 1 through 2 carbons or alkoxycarbonyl Where the alkyl group has 1 through 2 carbons, and trifluoromethyl;

NHCOOR where R is alkyl of 1 through 8 carbons, ethylpyrrolidinyl or phenyl; and R and R are hydrogen, methyl, ethyl, chlorine, bromine, fluorine, nitro, amino, dialkylamino where each alkyl group has 1 through 4 and preferably 1 through 2 carbons, cyano, alkoxy of 1 through 4 and preferably 1 through 2 carbons or alkoxycarbonyl where the alkyl group has 1 through 2 carbons, and trifluoromethyl; and

(c) non-toxic acid addition salts of the compounds of (a) and (b).

2. The method of claim 1 where the compound administered is a compound of the formula:

HCOOR where R is alkyl of 1 through 8 carbons, ethyl pyrrolidinyl or phenyl; and R and R are hydrogen, methyl, ethyl, chlorine, bromine, fluorine, nitro, amino, dialkylamino Where each alkyl group has 1 through 4 and preferably 1 through 2 carbons, cyano, alkoxy of 1 through 4 and preferably 1 through 2 carbons, alkoxycarbonyl where the alkyl group has 1 through 2 carbons and trifluoromethyl.

3. The method of claim 1 wherein the compound administered is a compound of the formula:

NHCOOR Where R is alkyl of 1 through 8 carbons, ethylpyrrolidinyl or phenyl; and R and R are hydrogen, methyl, ethyl, chlorine, bromine, fluorine, nitro, amino, dialkylamino where each alkyl group has 1 through 4 and preferably 1 through 2 carbons, cyano, alkoxy of 1 through 4 and preferably 1 through 2 carbons, alkoxycarbonyl where the alkyl group has 1 through 2 carbons and trifluoromethyl.

4. A pharmaceutical formulation selected from the group consisting of a tablet, capsule, powder packet, sirup, suspension, elixir and parenteral solution comprising an antidepressant effective amount of a compound selected from the group represented by the formulae:

#NHCOOR where R is alkyl of 1 through 8 carbons, ethyl pyrrolidinyl or phenyl; and R and R are hydrogen, methyl, ethyl, chlorine, bromine, fluorine, nitro, amino, dialkylamino where each alkyl group has 1 through 4 and preferably 1 through 2 carbons, cyano, alkoxy of 1 through 4 and preferably 1 through 2 carbons, alkoxycarbonyl where the alkyl group has 1 through 2 carbons and trifluoromethyl;

where R is alkyl of 1 through 8 carbons, ethylpyrrolidinyl or phenyl; and R and R are hydrogen, methyl, ethyl, chlorine, bromine, fluorine, nitro, amino, dialkylamino Where each alkyl group has 1 through 4 and preferably 1 through 2 carbons, cyano, alkoxy of 1 through 4 and preferably 1 through 2 carbons, alkoxycarbonyl Where the alkyl group has 1 through 2 carbons and trifluoromethyl and (c) a non-toxic acid addition salt of (a) and (b); and

and a non-toxic pharmaceutical carrier for said compound. 5. A pharmaceutical formulation of claim 4 wherein the active ingredient is a compound of the formula:

NHCOOR where R is alkyl of 1 through 8 carbons, ethyl pyrrolidinyl or phenyl; and R and R are hydrogen, methyl, ethyl, chlorine, bromine, fluorine, nitro, amino, dialkylamino Where each alkyl group has 1 through 4 and preferably 1 through 2 carbons, cyano, alkoXy of 1 through 4 and preferably 1 through 2 carbons, alkoxycarbonyl where the alkyl group has 1 through 2 carbons and trifluoromethyl.

6. A pharmaceutical formulation of claim 4 wherein the active ingredient is a compound of the formula:

COOR

where R is alkyl of 1 through 8 carbons, ethylpyrrolidinyl or phenyl; and R and R are hydrogen, methyl, ethyl, chlorine, bromine, fluorine, nitro, amino, dialkylamino where each alkyl group has 1 through 4 and preferably 1 through 2 carbons, cyano, alkoxy of 1 through 4 and preferably 1 through 2 carbons, alkoxycarbonyl where the alkyl group has 1 through 2 carbons and trifluoromethyl.

References Cited UNITED STATES PATENTS 3,337,571 8/1967 Gregory 424-263 STANLEY I. FRIEDMAN, Primary Examiner U.S. Cl. X.R. 424-300 

